The invention is more particularly applicable for use in an installation for analysing dangerous liquids, especially radioactive liquids, where the receptacles containing liquid samples are pneumatically transported in a network of pipes between various stations and in particular analysis stations. However, it is firstly essential to fill the receptacles and this is why one of these stations of the network is allocated to filling. This station mainly comprises at least one filling liquid elevator ended by a needle for piercing the receptacle and a sheath including a bottom pierced in front of the needle. The receptacle to be filled is laid in a cage sliding in the sheath which remains suspended at some distance from the bottom of the sheath for most of the filling operations and which is lowered to the bottom of the sheath so as to provoke the piercing of the bottom of the receptacle by means of the needle.
The drawbacks linked to this conception are linked to pollution of the casing of the receptacle, indeed the bottom of the sheath. The filling liquid elevator may in fact be subject to operating defects expressed by small projections of liquid which splash the receptacle and the bottom of the sheath, or simple oozings which flow along the needle and are deposited on the bottom of the receptacle around the piercing hole. The high speed (15 meters per second) acquired by the receptacles when carried in the pipes then generally provokes a dispersion of small drops in the pipes and brings about pollution likely to extend throughout the entire network owing in particular to movements of the displacement air.